This invention relates to a fuel injection nozzle assembly for use in externally ignited internal combustion engines of the air-fuel mixture-compressing type being provided with fuel injection into a suction tube of the engine.
The fuel injection valves built into the suction tube, which serves for the intake of air, or, the engine block are heated up strongly, especially after stopping the engine, by the heat extending from the hot engine block and the exhaust pipes. The temperature to which the fuel injection nozzle is thus brought corresponds to a vapor pressure of 4 and 5 bar depending on the kind of fuel used. Because of technical requirements in controlling the amount of fuel, the opening pressure of the fuel injection valves must not surpass a determined pressure, for example 3.5 bar; in consequence whereof fuel vaporizes into the nozzle ducts. The share of fuel thus lost must be replaced when restarting the still luke-warm or cooled-down engine. This results in considerable starting time-lags, or the engine must be restarted several times and does not idle smoothly due to failure of the nozzle to spray the fuel, or to irregular spray of fuel from the nozzle.